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A comparative study of two different approaches for the incorporation of silver nanoparticles into layer-by-layer films.

Rivero PJ, Goicoechea J, Matias IR, Arregui FJ - Nanoscale Res Lett (2014)

Bottom Line: In this work, a comparative study about the incorporation of silver nanoparticles (AgNPs) into thin films is presented using two alternative methods, the in situ synthesis process and the layer-by-layer embedding deposition technique.The influence of several parameters such as color of the films, thickness evolution, thermal post-treatment, or distribution of the AgNPs along the coatings has been studied.Cross-sectional transmission electron microscopy micrographs, atomic force microscopy images, and UV-vis spectra reveal significant differences in the size and distribution of the AgNPs into the films as well as the maximal absorbance and wavelength position of the localized surface plasmon resonance absorption bands before and after thermal post-treatment.

View Article: PubMed Central - HTML - PubMed

Affiliation: Nanostructured Optical Devices Laboratory, Electric and Electronic Engineering Department, Public University of Navarra, Edif. Los Tejos, Campus Arrosadía, Pamplona 31006, Spain.

ABSTRACT
In this work, a comparative study about the incorporation of silver nanoparticles (AgNPs) into thin films is presented using two alternative methods, the in situ synthesis process and the layer-by-layer embedding deposition technique. The influence of several parameters such as color of the films, thickness evolution, thermal post-treatment, or distribution of the AgNPs along the coatings has been studied. Thermal post-treatment was used to induce the formation of hydrogel-like AgNPs-loaded thin films. Cross-sectional transmission electron microscopy micrographs, atomic force microscopy images, and UV-vis spectra reveal significant differences in the size and distribution of the AgNPs into the films as well as the maximal absorbance and wavelength position of the localized surface plasmon resonance absorption bands before and after thermal post-treatment. This work contributes for a better understanding of these two approaches for the incorporation of AgNPs into thin films using wet chemistry.

No MeSH data available.


ISS of the AgNPs into LbL films. ISS of the AgNPs into LbL films as a function of the number of L/R cycles and the pH (7.0 and 9.0) of the dipping polyelectrolyte solutions (PAH and PAA, respectively).
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Figure 2: ISS of the AgNPs into LbL films. ISS of the AgNPs into LbL films as a function of the number of L/R cycles and the pH (7.0 and 9.0) of the dipping polyelectrolyte solutions (PAH and PAA, respectively).

Mentions: In Figure 2, two different pH values of the PAA, pH 7.0 and 9.0, are used to show how the silver nanoparticles are synthesized into the LbL films. A color change from transparent to yellow orange with a characteristic absorption band around 420 nm (see Table 1) has been pointed as an interesting result to corroborate the ISS of the silver nanoparticles into the polymeric film obtained by the LbL assembly. It is possible to appreciate the difference between a glass slide with only polymeric coating [PAH/PAA]40 obtained by the LbL assembly at pH 7.0 or 9.0 (totally transparent) and the color evolution after the successive L/R cycles at these two pH values. When a higher number of L/R cycles have been performed, a better definition of the LSPR absorption band around 420 nm can be observed which is indicative that AgNPs have been synthesized in the films. It has been demonstrated that LbL films at pH 9.0 show a dramatically more intense orange coloration in comparison with LbL films at pH 7.0 after the same number of L/R cycles.In Figure 3, UV-vis spectra of the LbL films are shown after the ISS process of the AgNPs from 1 to 4 L/R cycles (solid lines) at pH 9.0 and only for 4 L/R cycles (dash line) at pH 7.0 in order to compare the great difference in intensity of the LSPR absorption band as a function of the pH value.An important consideration is the presence of the LSPR absorption maximum at a wavelength of 424.6 nm which is indicative that AgNPs with a spherical shape have been synthesized into the LbL films. In addition, an increase in the intensity of the LSPR absorption bands at this wavelength position is observed when the number of L/R cycles is increased due to a higher amount of AgNPs incorporated into the LbL films. This aspect was previously corroborated in Figure 2 because the LbL thin films with a higher number of L/R cycles showed a better definition of the orange coloration.


A comparative study of two different approaches for the incorporation of silver nanoparticles into layer-by-layer films.

Rivero PJ, Goicoechea J, Matias IR, Arregui FJ - Nanoscale Res Lett (2014)

ISS of the AgNPs into LbL films. ISS of the AgNPs into LbL films as a function of the number of L/R cycles and the pH (7.0 and 9.0) of the dipping polyelectrolyte solutions (PAH and PAA, respectively).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4066310&req=5

Figure 2: ISS of the AgNPs into LbL films. ISS of the AgNPs into LbL films as a function of the number of L/R cycles and the pH (7.0 and 9.0) of the dipping polyelectrolyte solutions (PAH and PAA, respectively).
Mentions: In Figure 2, two different pH values of the PAA, pH 7.0 and 9.0, are used to show how the silver nanoparticles are synthesized into the LbL films. A color change from transparent to yellow orange with a characteristic absorption band around 420 nm (see Table 1) has been pointed as an interesting result to corroborate the ISS of the silver nanoparticles into the polymeric film obtained by the LbL assembly. It is possible to appreciate the difference between a glass slide with only polymeric coating [PAH/PAA]40 obtained by the LbL assembly at pH 7.0 or 9.0 (totally transparent) and the color evolution after the successive L/R cycles at these two pH values. When a higher number of L/R cycles have been performed, a better definition of the LSPR absorption band around 420 nm can be observed which is indicative that AgNPs have been synthesized in the films. It has been demonstrated that LbL films at pH 9.0 show a dramatically more intense orange coloration in comparison with LbL films at pH 7.0 after the same number of L/R cycles.In Figure 3, UV-vis spectra of the LbL films are shown after the ISS process of the AgNPs from 1 to 4 L/R cycles (solid lines) at pH 9.0 and only for 4 L/R cycles (dash line) at pH 7.0 in order to compare the great difference in intensity of the LSPR absorption band as a function of the pH value.An important consideration is the presence of the LSPR absorption maximum at a wavelength of 424.6 nm which is indicative that AgNPs with a spherical shape have been synthesized into the LbL films. In addition, an increase in the intensity of the LSPR absorption bands at this wavelength position is observed when the number of L/R cycles is increased due to a higher amount of AgNPs incorporated into the LbL films. This aspect was previously corroborated in Figure 2 because the LbL thin films with a higher number of L/R cycles showed a better definition of the orange coloration.

Bottom Line: In this work, a comparative study about the incorporation of silver nanoparticles (AgNPs) into thin films is presented using two alternative methods, the in situ synthesis process and the layer-by-layer embedding deposition technique.The influence of several parameters such as color of the films, thickness evolution, thermal post-treatment, or distribution of the AgNPs along the coatings has been studied.Cross-sectional transmission electron microscopy micrographs, atomic force microscopy images, and UV-vis spectra reveal significant differences in the size and distribution of the AgNPs into the films as well as the maximal absorbance and wavelength position of the localized surface plasmon resonance absorption bands before and after thermal post-treatment.

View Article: PubMed Central - HTML - PubMed

Affiliation: Nanostructured Optical Devices Laboratory, Electric and Electronic Engineering Department, Public University of Navarra, Edif. Los Tejos, Campus Arrosadía, Pamplona 31006, Spain.

ABSTRACT
In this work, a comparative study about the incorporation of silver nanoparticles (AgNPs) into thin films is presented using two alternative methods, the in situ synthesis process and the layer-by-layer embedding deposition technique. The influence of several parameters such as color of the films, thickness evolution, thermal post-treatment, or distribution of the AgNPs along the coatings has been studied. Thermal post-treatment was used to induce the formation of hydrogel-like AgNPs-loaded thin films. Cross-sectional transmission electron microscopy micrographs, atomic force microscopy images, and UV-vis spectra reveal significant differences in the size and distribution of the AgNPs into the films as well as the maximal absorbance and wavelength position of the localized surface plasmon resonance absorption bands before and after thermal post-treatment. This work contributes for a better understanding of these two approaches for the incorporation of AgNPs into thin films using wet chemistry.

No MeSH data available.